JP2005503493A - Flexible press cover and shoe press roll having such a flexible press cover - Google Patents

Abstract

The present invention provides a flexible press jacket for use in a shoe press roll for dewatering or smoothing a continuous fiber web.
A press jacket according to the present invention includes a plastic layer (30) and reinforcing members (31, 32) embedded therein. The press jacket (10) is provided with an additional stiffener (34) in at least one of its two end sections (E), thereby enabling the jacket of a rotatable support element (eg spreader ring (27)). It is possible to attach a press jacket to the surface. The system for securing the press jacket (10) to the support element (27) does not require a fastening element associated with the jacket surface.
[Selection] Figure 1

Description

【Technical field】
[0001]
The present invention relates to a flexible press cover intended for shoe press rolls.
[Background]
[0002]
This type of shoe press roll is used to dewater or calender a moving fiber web, in particular a paper or cardboard web. The flexible press cover comprises a plastic layer, preferably made from polyurethane, and, as a reinforcing means, a reinforcement ("conventional") embedded in the plastic layer. The reinforcement can be formed as a woven fabric, but preference is given to what is known as a raid fabric comprising longitudinal filaments parallel to the axial direction and wound circumferential filaments. Circumferential filaments can be wound into a plastic layer outside the longitudinal filaments (see EP0330680 = US Pat. No. 5,134,010, PH04378). However, the opposite arrangement is also possible (see WO 95/29293, Tamfeld).
With respect to the prior art, reference is made to the following other documents.
[0003]
D1: DE 3546650 C2 (PH04164A) specification
D2: DE 29702362 (PH10287) specification
D3: DE 19633543 (PH10368) specification
As is well known, shoe press rolls comprise stationary support elements. Two cover bearing disks for the flexible press cover are rotatably mounted on the stationary support element. Furthermore, in order to form a press nip that extends in the web running direction, a radially displaceable press shoe that can press the rotating press cover onto the opposing roll is arranged on the support element. It is important that, together with the support element, the press cover and the cover bearing disc define a liquid-tight closed interior space.
[Patent Document 1]
EP0330680
[Patent Document 2]
US Pat. No. 5,134,010
[Patent Document 3]
DE 3546650 C2
[Patent Document 4]
DE 29702362
[Patent Document 5]
DE 196353543
[Patent Document 6]
WO95 / 29293
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
[0004]
According to document D1, in order to achieve a fluid-tight connection between the press cover end area and one of the cover bearing discs, the end area is bent radially inwardly upwards and the clamping element is used to It is configured to press the area onto the outer edge of the cover bearing disc.
[0005]
This configuration has been tried and tested in practice. However, a large number of recesses must be provided in the edge zone of the press cover, which is disadvantageous in that a tongue remains between these recesses. In some cases, difficulties also arise in achieving the most accurate circularity of the press cover.
[0006]
According to FIGS. 3 and 4 of document D2, an attempt is made to avoid deformation of the end region of the press cover described in D1. Since each of the two press cover end regions has a normal cylindrical shape, it is not necessary to manufacture the recess and the tongue. A cylindrical press cover end region is configured to be clamped between the inner expandable (ie expandable diameter) spreader ring and the outer ring. However, replacement of a worn press cover with a new press cover requires more skill, and such outer rings are often fragile.
[0007]
According to FIGS. 2 to 4 of document D3, an annular circumferential groove is provided on the outer peripheral surface of the cover bearing disc, specifically by means of a clamp band or by multiple turns of high-strength filaments or by a shrink ring. Of the annular region is pressed into the annular circumferential groove. If the cover provided according to FIG. 1 is omitted, there is no fragile outer ring. Nevertheless, this known solution is not practically accepted.
[0008]
The invention is based on the object of further developing a flexible press cover of the design described at the outset so that as many of the following requirements as possible are fulfilled.
[0009]
a) Production of recesses and tongues in the end area of the press cover should be unnecessary.
[0010]
b) Installation of the press cover end area of each cover support disc should be performed with the least possible effort and can be used at the two roll ends if the mounting operation is carried out in a papermaking machine. The fact that the mounting space is often very limited must be taken into account.
[0011]
c) The most precise circularity of the press cover to be installed last should be achievable.
[0012]
d) The outer peripheral surface of the press cover should not contain any fixing elements, for example outer rings.
[Means for Solving the Problems]
[0013]
In order to solve the above-mentioned problems, the present invention is intended for a shoe press roll used for dewatering or calendering a moving fiber web, and a plastic layer (30) and reinforcing means in the plastic layer. A flexible press cover (10) having a “conventional” reinforcement (31, 32) embedded as a press cover (10) in at least one of its two end regions (E) Comprises additional reinforcing means (34) making it suitable to fix the press cover to a rotatable support element (eg spreader ring 27) of the shoe press roll, preferably to the outer peripheral surface of the support element. It is characterized by.
【The invention's effect】
[0014]
According to the invention, the above object is achieved in principle in that the flexible press cover has additional reinforcing means in at least one of its two end regions. As a result, in the end region, the circumferential tensile strength and tensile stiffness are relative to the conventional end region so that it is no longer necessary to clamp the press cover end region between the two components. Will be increased. Instead, the press cover according to the invention is suitably fixed to the outer peripheral surface of the rotatable support element belonging to the cover bearing disc without the aid of outer rings, clamp bands, clamp filaments, etc. (Claim 1). . In the most beneficial case, the arrangement for fixing the press cover to the support element described above does not completely comprise any type of fixing element associated with the outer surface of the cover (claim 2).
[0015]
According to the invention, several advantages can be achieved, ie the shape of the press cover end region remains completely or at least approximately cylindrical. That is, during the installation of the press cover, there is no need to deform the end area of the press cover, and therefore there is no need to manufacture the recess and tongue. Joining the press cover end region to the radially outer portion or the region of the cover bearing disk can be performed in a manner similar to, or at least very similar to, joining of the two metal components.
[0016]
In this way, the mounting of the press cover to the cover support disk can be performed more easily than before, that is, with less effort than before, and as a result, if necessary, even an inexperienced person can perform the mounting work. I can leave it to you. A further important advantage is that no outer ring (which rotates with the press cover) is required. Similarly, the clamping elements required according to D1 are omitted, which makes it easier to work in confined spaces in the paper machine.
[0017]
The press cover end region advantageously has a constant thickness measured along an envelope parallel to the axial direction. In general, in the press cover to be mounted last, not only the outer peripheral surface but also the inner peripheral surface (having an additional reinforcing portion) of the end region of the press cover is therefore cylindrical (Claim 3). However, you can do different things if you want. Specifically, it may be advantageous to design the inner peripheral surface of the end region of the press cover to be slightly conical by increasing the inner diameter to the outside or the inside (Claim 4). This makes it easier to fix the press cover end region to any kind of annular support element belonging to the cover bearing disc (or directly to the bearing disc). In both cases it may be advantageous to provide a support element that can be expanded in diameter, i.e. expanded. However, it is also possible to use a ring that cannot be spread, for example a mounting ring that is inserted into a new press cover incorporated outside the shoe press roll (see DE 101 38 527.7).
[0018]
According to claims 6 to 32, the present invention is applicable to flexible press covers having different conventional reinforcements, in particular woven or raid fabric reinforcements. In claims 6 to 32, different embodiments of the additional reinforcement are also defined, which can be formed as additional or reinforcing reinforcements. As an alternative or in addition, a material having a higher elastic modulus in the circumferential direction can be used. Another possibility is to integrate the reinforcing ring into at least one press cover end region. The purpose of all these measures is to reduce the circumferential extensibility of the press cover end region compared to the prior art.
According to claims 33 to 41, protection is also claimed for a finished shoe press roll having a flexible press cover formed according to the present invention. In this case, at least one of the two cover bearing discs can be adapted in one way or in another way to a press cover end region formed according to the invention. Details will be further described below in the course of the explanation of the drawings.
BEST MODE FOR CARRYING OUT THE INVENTION
[0019]
Exemplary embodiments of the present invention are described below with reference to the drawings.
[0020]
FIG. 1 shows the fixation of the flexible press cover to only one of the two end regions of the flexible press cover 10 and the rotatable cover bearing disc 20 of the shoe press roll. The rotatable cover bearing disc is attached to the invisible support element by means of a rolling contact bearing 21 in a known manner. Similarly, the press shoe is not shown, and the press cover 10 can be pressed to the opposing roll using this. These and other well-known details of the shoe press device can be understood, for example, from DE 195 27 762 (PH 10178).
The press cover 10 consists essentially of, for example, a polyurethane plastic layer 30, and a conventional reinforcing material is embedded in the plastic layer as a reinforcing means, and the reinforcing material is longitudinally parallel to the axial direction in a well-known manner. A filament 31 and a circumferential filament 32 wound thereon are provided. The thickness d of the press cover 10 is selected so that a groove or blind hole 33 can be provided in the press zone P. In the end region E, the press cover 10 has substantially the same thickness d as the press zone P. In the end region E, additional circumferential filaments 34 with the highest possible tensile strength and tensile stiffness (high modulus of elasticity) are provided as additional reinforcements (ie in addition to the conventional reinforcements 31, 32). Embedded in the plastic layer 30.
According to the present invention, the circumferential filament 34 forms an additional reinforcement made from a high strength plastic or metal filament or wire. Compared to the conventional reinforcement circumferential filament 32, the additional circumferential filament or wire 34 has a larger filament diameter and / or higher tensile strength, in particular a higher elastic modulus (eg Kevlar). (Kevlar)). However, it is also possible to select for the filaments 32 and 34 the same diameter and / or the same material, preferably a material with a relatively high elastic modulus. Furthermore, the plastic layer can be formed from a material with an increased elastic modulus. Between the end region E and the press zone P, the press cover 10 may have a smaller thickness zone in order to precisely increase the flexibility of the press cover where increased deformation occurs during operation. it can.
[0021]
The cover bearing disc 20 includes an integrally formed collar 22 and an extension ring 23 screwed thereto. Collar 22 and ring 23 engage around rolling contact bearing 21 and support an axially displaceable clamping ring formed as an annular piston 24 outside the collar and ring. The three above-mentioned components 22, 23 and 24 are shaped such that an annular space 25 in which a pressurized medium can be applied is formed between the three components. As a result, the annular piston 24 can be displaced outwardly in a hydraulic or pneumatic manner in parallel with the roll axis. A seal ring 26 is used to seal from the annular space 25.
[0022]
In order to connect the press cover 10 to the cover support disc 20, a spreader ring 27 is prepared. The spreader ring has a cylindrical outer peripheral surface provided with a recess if necessary, and this outer peripheral surface engages with the cylindrical inner peripheral surface of the press cover end region E. The spreader ring 27 has a conical inner peripheral surface that interacts with the conical outer peripheral surface of the annular piston 24. In the case of an axial displacement of the annular piston 24 (to the left in FIG. 1), the spreader ring 27 (supported axially by the cover bearing disc 28) is widened, so that a reliable liquid-tight connection is established between the press cover 10 and the cover. It is formed between the support disk 20. Due to the additional stiffener 34, the outer clamp link is no longer required in the press cover end area.
[0023]
The axial displacement of the annular piston 24 can also be performed using screws (shown at 28). This type of screw 28 can also be used to axially fix the annular piston after it has been displaced hydraulically or pneumatically. FIG. 2 shows the spreader ring 27 from the outside. This ring is given the ability to spread by slots 29 machined alternately from both sides, and a highly elastic filler is provided in this ring to ensure the required hermetic seal of the roll interior space.
[0024]
FIG. 3 differs from FIG. 1 in that an end region E of the press cover 10 ′ is provided with a bead 30A protruding inward in the radial direction that fits into the folded recess in the spreader ring 27 ′. In this way, the accuracy with which the press cover 10 ′ is fixed to the support disk 20 in the axial direction is improved.
[0025]
The press cover 10A of the exemplary embodiment shown in FIG. 4 is substantially the same as the press cover of FIG. 1, and only the length E ′ of the end area of the press cover is the larger axial length of the spreader ring 27A. Correspondingly somewhat enlarged. Again, the cover bearing disc 20 </ b> A has a collar 22 </ b> A for accommodating the rolling contact bearing 21. There is a simple clamp ring 24A between the collar 22A and the spreader ring 27A. The clamp ring 24A is axially displaced outwardly using only the screw 28, and expands the outer diameter of the spreader ring having a conical outer peripheral surface. The conical outer peripheral surface is a reliable member for the press cover 10A. In order to form a connection, it interacts with the conical inner peripheral surface of the spreader ring 27A. A collar 27B is integrally formed on the spreader ring 27A, which makes it easy to fix the press cover in the axial direction on the bearing disk 20A again.
[0026]
In the shoe press roll according to the present invention, both ends of the roll can be configured according to FIG. Another possibility is to construct one end of the shoe press roll according to FIG. 1 or FIG. 3, but on the other hand according to FIG. 4 or according to FIG. 5 or FIG. Forming the end.
[0027]
The press cover 10B of the exemplary embodiment shown in FIG. 5 has an inner peripheral surface of the end region that is not continuously cylindrical, is slightly conical at a short distance from the outside, and has an inner diameter from the outside to the inside. It differs from the press cover 10A of FIG. 4 only in the fact that it becomes smaller.
[0028]
This makes it easier to insert the mounting ring 40 having a corresponding conical outer peripheral surface. This insertion of the ring 40 (and fixing of the ring of the press cover 10B by means of an adhesive, for example) can be performed outside the shoe press roll, i.e. before removing the worn and replaceable press cover. preferable. In order to fix the mounting ring 40 that supports the press cover 10B to the cover support disc 20B, the following is performed: the outer peripheral surface of the cover support disc 20B is offset by 41. The inner circumferential surface of the reinforcing ring 40 has a corresponding offset in the illustrated embodiment, with a larger inner diameter in the axial direction from the inside to the outside, following a relatively small inner diameter D. In this way, the press cover 10B can be pressed onto the cover bearing disc 20B together with the mounting ring 40 mounted in advance in the direction of arrow P over the entire stationary support element (not shown). This is possible due to the fact that the aforementioned relatively small inner diameter D of the ring 40 is still somewhat larger than the external dimensions of the stationary support element, including the press shoe and other accessories. In order to screw the ring 40 to the cover support disc 20B, the following is performed: the bushing 42 is rotatably mounted in the hole of the cover support disc 20B. A nose flange 43 is integrally formed at the inner end of the bush 42, and a radial pin 44 is inserted into the outer end. In the illustrated position of the bush 42, the nose of the nose flange 42 acts on the inner end of the ring 40. However, as a result of rotation of the bushing 42, the nose allows the reinforcing ring to pass when inserted in the direction of arrow P. A screw 28 is provided to secure the mounting ring 40 (together with the press cover 10B) to the cover bearing disc 20B using the nose flange 43 described above. It goes without saying that a plurality of such configurations are distributed over the circumference of the cover support disc 20B.
[0029]
FIG. 6 shows a simplified alternative to FIG. In this figure, the mounting ring 40 'has a smooth inner peripheral surface (without the offset 41 shown in FIG. 5), and the bush 42 is omitted. The mounting ring 40 ′ is screwed to the cover bearing disc 20 ′ by a simple stud 45. However, this design generally requires a smaller inner diameter D ′ of the mounting ring 40 ′ than in FIG. When the press cover is retracted, it is nevertheless possible to arrange some of these accessories so that they can be moved by the support elements so that the mounting ring 40 'can pass through the stationary support elements with the accessories. May be necessary. See similar patent application DE 101 38 527.7.
[0030]
In order to fix the press cover 10C to the mounting ring 40 ', the following is performed. That is, a conical outer peripheral surface that tapers outward is applied to the mounting ring. Furthermore, in the press cover end region E ″, the circumferential filaments 32A and / or 34A are entangled with increased prestress, so that the end region E ″ likewise tapers conically in the outward direction. . The press cover 10C is fixed on the mounting ring 40 'in the same manner as the vehicle tire is fixed to the rim. The press cover design of the circumferential filament that is wound with increased prestress can also be combined with a mounting ring with a cylindrical outer peripheral surface.
[0031]
FIG. 7 shows a press cover 11 that is modified with respect to FIG. 1, whose conventional reinforcement (different from FIG. 1) is a longitudinal direction parallel to the axial direction arranged outside the circumferential filament 32. It has a filament 35 (corresponding to WO'293). As an additional reinforcement, a circumferential filament 36 is provided which is preferably wound from the inside on conventional reinforcements 32, 35. As an alternative or in addition, circumferential filaments 36 ′ wound from the outside can be provided on conventional reinforcements 32, 35 to further strengthen the press cover end region. The press cover 12 shown in FIG. 8 has a woven fabric 37 as a conventional reinforcing material. As an additional reinforcement in the end area of the press cover, a circumferential filament 38 is provided on the woven fabric 37 which is wound from the outside. Alternatively or additionally, circumferential filaments 38 ′ arranged radially inside can be provided.
[0032]
In the exemplary embodiment according to FIGS. 7 and 8, both press cover end regions can be designed identically. In contrast, the variant shown in FIG. 9 can be provided on only one of the two press cover ends. This alternative form is obtained from the manufacturing method according to EP 0330680 (method of manufacturing a press cover outside the casting cylinder). Specifically, FIG. 9 shows a press cover 13 in which the conventional reinforcing members 31 and 32 correspond to the conventional reinforcing member of the press cover 10 shown in FIG. The end region of the illustrated press cover 13 has a thickened portion 30A that protrudes inward in the radial direction, as in FIG. In this thickened part is placed an additional reinforcement which can be formed as a woven fabric or as a raid fabric (as shown), which is wound on the longitudinal filament 39 parallel to the axial direction. And a circumferential filament 39 ′. Furthermore, a thickened portion (not shown) protruding outward in the radial direction similar to the thickened portion of FIG. 1 or FIG. 3 can be provided.
[0033]
FIG. 10 shows a press cover 50 according to the invention in which the end region has no thickening. In this figure, the additional reinforcement is formed by a circumferential filament 32 ′ that is wound more tightly into the end region than the circumferential filament 32 disposed outside the end region. The circumferential filaments 32 and 32 'can be composed of the same material. Alternatively, the circumferential filament 32 ′ can be formed from a material with an increased elastic modulus. Furthermore, in the end region, the plastic layer 30 can be manufactured from a material with an increased elastic modulus.
[0034]
FIGS. 11 to 15 show an embodiment of a press cover according to the invention in which a reinforcing ring (plastic or metal) is integrated into the end area of the press cover as an additional reinforcement. According to FIG. 11, the thickness d of the axially outer region 52 of the reinforcing ring 51 is substantially the same as or greater than the thickness of the end region E of the press cover 10 of FIG. The axially inner region 53 is substantially thinner and overlaps the end of the press cover 54 originally manufactured in a conventional manner (EP'680) with its reinforcements 31,32. The ring 51 is secured by casting an additional plastic layer 55 and simultaneously winding an additional circumferential filament 56. The press cover 54 is fixed to the cover bearing disc in the same manner as in FIG. 1 or FIG. 4 or by screws that directly engage the reinforcing ring 51 in the axial direction (see threaded hole 59).
[0035]
FIG. 12 shows that the axially outer region of the reinforcing ring 51A is thinner than the thickness d of the finished press cover end region and that the reinforcing ring has additional circumferential filaments 56 over its entire length. 11 differs from FIG. 11 in that it is covered by an additional plastic layer 55A.
[0036]
FIG. 13 shows the end region of a press cover 60 manufactured according to WO'293 with a reinforcing ring 61. A casting cylinder 62 is shown schematically with an inner peripheral surface 63. First, during the manufacture of the press cover 60, the longitudinal filament 64 is tightened using the reinforcing ring 61 fixed to the casting cylinder 62. Next, the plastic layer 65 is cast, and at the same time, the circumferential filament 66 is wound on the longitudinal filament 64 and the reinforcing ring 61 from the inside. In order to fix the press cover 60 to a cover bearing disc (not shown), the reinforcing ring 61 has a flange 67 protruding radially inward. Alternatively, a flange 68 projecting radially outward may be provided.
[0037]
FIG. 14 shows a method for manufacturing the press cover 70 having the reinforcing rings 71 and 72. This manufacturing method corresponds to the manufacturing method of EP'680, and is manufactured by the casting cylinder 73 on the outer peripheral surface. Unlike EP'680, instead of a clamp ring, reinforcing rings 71 and 72 are provided, which are first used to clamp the longitudinal filament 74, and the plastic layer 75 is cast to form a circle. After the circumferential filament 76 is wound at the same time, it remains a component of the press cover 70. Reliable fixing of the reinforcing rings 71 and 72 of the press cover 70 is achieved by means of a longitudinal filament 74 (disclosed in EP'680) which is meandered through the reinforcing rings 71, 72 and then tensioned, further disclosed in EP'680. This is achieved by the fact that the circumferential filament 76 is wound on a reinforcing ring with a certain prestress. FIG. 14 also shows the situation where the casting nozzle 77 moves from one end of the casting cylinder 73 to the other during the casting operation, while the cylinder rotates simultaneously.
[0038]
One reinforcing ring 71 has a flange 71 a protruding inward in the radial direction supported by one end of the casting cylinder 73. The other reinforcing ring 72 has a radially outwardly projecting flange 72 a with which a clamping screw 78 engages to tension the longitudinal filament 74.
[0039]
FIG. 15 shows the press cover 70 manufactured according to FIG. 14 in the finished state, mounted on the cover bearing disks 79 and 80. In this case, the flanges 71a and 72a are used each time to fix the press cover to the bearing disc using screws 81, 82. Each of the two reinforcing rings 71 and 72 is centered on the outer peripheral surface of the cover support disk. In order to make it easier to retract the press cover 70 in the axial direction (arrow P), the diameter of the outer peripheral surface of the left support disk 79 (FIG. 15) is smaller than the diameter of the right support disk 80. Thus, the casting cylinder 73 of FIG.
[0040]
In the case of the press cover 14 shown in FIG. 16 (its conventional reinforcement is not shown), the additional reinforcement is formed as an end section 16 of the press cover that is folded (or folded) inwardly. Additional reinforcement 15 is provided in the press cover. As FIG. 16 shows, the inner peripheral surface of the inner folded end section 16 is conical with an inner diameter that increases in the inner direction. As a result, the press cover 14 is fixed to the cover support disks 20C and 20D in the same manner as the vehicle tire is fixed to the rim. One press cover end section preferably sits directly on a cover bearing disc 20D having a corresponding conical outer peripheral surface. The other end section sits on a clamp ring 17 which likewise has a corresponding conical outer peripheral surface and can be displaced axially parallel by the cover bearing disc 20C. The plurality of ring segments 18 can be inserted into the cover support disc 20C in the radial direction from the outside to the inside. A screw 19 extends through the segment and can be used to clamp the press cover end section between the clamp ring 17 and the ring segment 18.
[Industrial applicability]
[0041]
The present invention is suitable for a flexible press cover and a shoe press roll having such a flexible press cover.
[Brief description of the drawings]
[0042]
FIG. 1 is a partial longitudinal sectional view of a shoe press roll having a flexible press cover according to the present invention.
FIG. 2 is a partial view of a spreader ring belonging to a shoe press roll.
FIG. 3 is a drawing of another embodiment of FIG. 1;
4 is a drawing of another embodiment of FIG.
FIG. 5 is a drawing of another embodiment of FIG. 1;
6 is a drawing of another embodiment of FIG.
7 is a longitudinal cross-sectional view of various modifications of the press cover end region. FIG.
FIG. 8 is a longitudinal cross-sectional view of various modifications of the press cover end region.
FIG. 9 is a longitudinal cross-sectional view of various modifications of the press cover end region.
FIG. 10 is a longitudinal cross-sectional view of various modifications of the press cover end region.
11 is a longitudinal cross-sectional view of various modifications of the press cover end region. FIG.
12 is a longitudinal sectional view of various modifications of the press cover end region. FIG.
13 is a longitudinal sectional view of various modifications of the press cover end region. FIG.
FIG. 14 shows a method of manufacturing a press cover on the outer peripheral surface of a casting cylinder.
15 is a drawing of a press cover in a final mounted state manufactured according to FIG. 14;
FIG. 16 is a drawing of still another embodiment of a shoe press roll having a flexible press cover according to the present invention.
[Explanation of symbols]
[0043]
30 ... Plastic layer
31, 32 ... Reinforcing material
10 ... Flexible press cover
E ... Edge region
27 ... Spreader ring 27
34 ... Strengthening means

Claims (41)

A “conventional” reinforcement intended for shoe press rolls used for dewatering or calendering a moving fibrous web and embedded as a reinforcing means within the plastic layer (30) 31, 32) a flexible press cover (10),
In at least one of its two end regions (E), a press cover (10) is placed on the rotatable support element (eg spreader ring 27) of the shoe press roll, preferably on the outer periphery of the support element. Flexible press cover, characterized in that it has additional reinforcing means (34) that make it suitable for fixing to a surface. The flexible press cover according to claim 1, characterized in that the arrangement for fixing the press cover (10) to the support element (27) does not include a fixing element associated with the outer peripheral surface. 3. A flexible press cover according to claim 1 or 2, characterized in that the inner peripheral surface of the press cover end region E with an additional reinforcement (34) is cylindrical. The inner peripheral surface of the end region of the press cover with an additional reinforcement (34) is conical and has an inner diameter (Fig. 5 or 6) which increases or decreases in the outward direction. The flexible press cover according to 1 or 2. 5. A device according to claim 3 or 4, characterized in that, as is known per se, the above-mentioned support element (27, 27A) can be expanded, the diameter (Figs. 1-4) can be expanded. Flexible press cover. The conventional reinforcement of the flexible press cover comprises a woven fabric (37) or “raid fabric”, which is a longitudinal filament (31) parallel to the axial direction and a circumferential filament (32). A flexible press cover comprising: the additional reinforcement is formed as an additional reinforcement (34; 36; 38; 39 '). A flexible press cover as described in 1. 7. A flexible press cover according to claim 6, characterized in that the additional reinforcement comprises circumferential filaments (34; 38) wound from outside on a conventional reinforcement. 8. The additional reinforcing material according to claim 6 or 7, characterized in that it comprises a circumferential filament (36) wound from the inside (Fig. 7) on a conventional reinforcing material (32, 35). The flexible press cover as described. Said additional reinforcement is provided with a thickened bead (30A) with an inner diameter smaller than the inner diameter of the remaining press cover (FIGS. 3, 9), preferably only in one of the two end regions of the press cover (13). The flexible press cover according to claim 1, wherein the flexible press cover is provided. Additional stiffeners were wound in the bead (30A), for example in the longitudinal filament (39) parallel to the axial direction and wound on the longitudinal filament (FIG. 9). The flexible press cover according to claim 9, wherein the flexible press cover is provided in a woven fabric or a woven fabric. The additional reinforcement, for example, with increased winding density and / or increased filament thickness (FIG. 10), additional circumferential filaments (32) forming a series of conventional circumferential filaments (32). The flexible press cover according to claim 1, wherein the flexible press cover is formed from 7. A flexible press cover according to claim 6, characterized in that the additional reinforcement comprises at least one band, for example a woven band. The end region (E) with an additional reinforcement (34) has a greater thickness (d, Fig. 1) than the adjacent press cover region. A flexible press cover according to Item. Flexible press cover according to claim 1 or 2, characterized in that the additional reinforcement is formed as an end section (16) of the press cover (14) which is folded inwardly. 15. A flexible press cover according to claim 14, characterized in that an additional reinforcement (15) is provided in the end section (16). 16. A flexible press cover according to claim 14 or 15, characterized in that the inner peripheral surface of the end section (16) which is folded inwardly is conical with an inner diameter which increases inwardly. 16. A flexible press cover according to claim 14 or 15, characterized in that the end section which is folded inwardly has a substantially cylindrical inner peripheral surface. Additional reinforcement means formed by at least one material used for the press cover end region (E) having a higher elastic modulus in the circumferential direction compared to the material of the remaining press cover region The flexible press cover according to any one of claims 1 to 5. 19. The reinforcement of the end region (E), in particular the circumferential filament (32 '), has an increased elastic modulus that is at least 15000 MPa, preferably at least 25000 MPa. Flexible press cover. 20. A flexible press cover according to claim 18 or 19, characterized in that, in the end region (E), the plastic layer (30) has an increased elastic modulus which is at least 200 MPa. 6. An additional strengthening means formed by at least one material used for the entire press cover having an increased elastic modulus in the circumferential direction. Flexible press cover. The flexible press cover according to claim 21, characterized in that the circumferential filament (32) has an increased modulus of elasticity of at least 15000 MPa, preferably at least 25000 MPa. In said additional reinforcement, the circumferential filaments (34; 36; 38; 39 ') have an increased elastic modulus that is at least 15000 MPa, preferably at least 25000 MPa. The flexible press cover of any one of these. In at least one end region (E ″), characterized by additional reinforcing means, wherein the circumferential filament (32A) is formed in a form of reinforced concrete (FIG. 6) so as to be entangled with increased prestress. The flexible press cover according to any one of claims 1 to 5. 25. A flexible press cover according to claim 24, characterized in that the end region (E ") tapers conically in the outward direction. 26. Flexible press cover according to claim 24 or 25, characterized in that the circumferential filaments (34A) of additional reinforcements are likewise wound with increased prestress. 7. Possible according to claim 1, characterized in that the additional strengthening means comprises a strengthening ring (51; 51 A; 61; 71, 72) prefabricated from plastic or metal. Flexible press cover. 28. The flexible press cover of claim 27, wherein at least a portion of the reinforcement ring is cast into the press cover as seen in a cross-section of the reinforcement ring. 29. A flexible press cover according to claim 28, characterized in that the reinforcing ring is secured to the press cover using reinforcing filaments (56; 64, 66; 74, 76). 30. Flexible press cover according to claim 28 or 29, characterized in that the reinforcing ring (51, 51A) is cast following the conventional casting of the plastic layer. 30. Flexible press cover according to claim 28 or 29, characterized in that the reinforcing ring (61; 71, 72) is cast at the same time as the conventional plastic layer is cast. The reinforcing ring has a flange (67 or 68, or 71a and 72a, respectively) for fixing the press cover to a rotatable support element belonging to the shoe press roll (eg cover bearing discs 79 and 80). The flexible press cover according to any one of claims 27 to 31. A shoe comprising a flexible press cover constructed according to any one of claims 1 to 32 and having a rotatable cover bearing disc (20) attached to a stationary support element at each end of the roll. In the press roll,
a) at least one of the cover support discs (20) comprises a clamp ring (24 or 24A) which can be displaced axially on the outer peripheral surface of the cover support discs;
b) the clamping ring has a conical outer surface that engages the conical inner surface of the expandable ring (27 or 27A);
c) the ring that can be spread is seated on the inner surface of the cover in the end region (E) of the press cover with an additional reinforcement (34);
d) The shoe press roll, wherein the configuration does not include a fixing element associated with the outer peripheral surface of the press cover. Shoe press roll according to claim 33, characterized in that the clamp ring (24A) can be displaced axially by means of a screw (28). Shoe press roll according to claim 33, characterized in that the clamp ring (24) can be displaced axially by a hydraulic chamber (25), as is known per se. 36. Shoe press roll according to any one of claims 33 to 35, characterized in that the spreader ring (27A) has a collar (27B) for fixing the press cover in the axial direction (Fig. 4). . At least one end of the roll is provided with a mounting ring (40, 40 ') for connecting the press cover (10B; 10C) to the cover support disk (20B; 20'), Outside the press roll, it can be inserted into the end of the press cover with an additional reinforcement (34, 34A) and then (together with the press cover) can be fixed to the cover support disc (FIG. 5, FIG. 6) A shoe press roll according to the preamble of claim 33, characterized in that The mounting ring (40, 40 ') described above has a conical outer peripheral surface that matches the conical inner peripheral surface of the press cover end region with an additional reinforcement (34; 34A). The shoe press roll according to claim 37. The shoe press roll according to claim 37, wherein the mounting ring has a substantially cylindrical outer peripheral surface. 40. A tapered ring on the outside (claimed in claim 25 or 26) (FIG. 6), characterized in that a mounting ring (40 ′) can be inserted into the end region of the press cover. The shoe press roll according to any one of claims. 41. A shoe press roll according to any one of claims 37 to 40, characterized in that the mounting ring (40, 40 ') has a collar for fixing the press cover in the axial direction.